To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘Beyond 4G Network’ or a ‘Post LTE System’.
The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like.
In the 5G system, Hybrid FSK and QAM Modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.
FIG. 1 is a diagram showing a heterogeneous network according to the related art. An existing multi-radio access technology (multi-RAT) merging management method is an accessing method of selecting between heterogeneous networks, and performing transmission between a user equipment (UE) and an evolved node B (eNB) via a cellular macro communication network 110 and one of the millimeter wave (mmW) communication networks 130.
Referring to FIG. 1, a macro communication network 110 and a plurality of mmW communication networks 130 form a multi-RAT network. The macro communication network 110 may be various cellular communication networks including a long term evolution (LTE) communication network. The mmW communication network 130 may employ an mmW of 60 GHz and also use access points (APs). The macro communication network 110 and the mmW communication networks 130 may communicate using a control plane and a user plane. The mmW communication networks may be connected to each other with Xw interfaces. There are technologies of the related art, within one of which, for example, a client device uses communication capability information, i.e., available RAT information and stop/movement information, and data rate request, and determines a transmission link from among the cellular/Wi-Fi or mmW link, according to corresponding information.
FIG. 2 is a diagram showing a dual connectivity network according to the related art.
In a system of remote radio head (RRH) in a cellular communication system, a mobile device 250 can receive access via a small cell 240 or macro cell 230 such as an evolved node B (eNB). The macro cell 230 is connected to a mobility management entity (MME) 220 to receive network access from gateway/home subscriber server (GW/HSS) 210 via a core network. The small cell 240 also receive network access from the GW/HSS 210. It is assumed that the capacity of the Xw interface as an inter-eNB connection is sufficiently large and transmission is very small (less than 10 ms), assuming an ideal backhaul. Existing studies performed in 3rd Generation Partnership Project (3GPP) Release 12, e.g., small cell enhancement, dual connectivity, etc., have discussed a number of design options, such as a method of connecting data plane (or user plane) and control plane to a small cell 240 via a macro cell 230 as shown in FIG. 2, directly transmitting data from a core network via a to a small cell 240, etc. However, technologies of the related art have not resolved a control signaling delay that is caused when inter-eNB transmission path is a non-ideal backhaul.
Since the architecture of the small cell employing the mmW frequency band has a difference between the assumptions of the related art (e.g., an assumption of a non-ideal backhaul) and the real situation, there is a need to improve design to reduce the control channel delay and to enhance the data channel capacity.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.